Block-signaling system.



R1 C. MILLARD. BLOCK SIGNALING SYSTEM.

. APPLICATION FILED NOV. I2- 1914:l 1,241,873. Patented Oct. 2,1917.

2 SHEETS-SHEET l.

Suvenkoz attorneys R. C. MILLARD. BLOCK SIGNALING SYSTEM. APPLICATION HLED Nov.12. 1'914.

Patented Oct. 2, 1917.

2 SH ETS-SHEET 2- @wi/buenas 'narra ROBLEY C. MILLARD, 0F ATLANTA, GEORGIA.

BLOCK-SIGNALING- SYSTEM.

Specification of Letters Patent.

Patented Oct. 2, 191 *7.

Application filed November 12, 1914. Serial No. 871,766.

To all whom t may concern:

Be it known that I, ROBLEY C. MILLARD, a citizen of the United States, residinr at Atlanta, in the county of Fulton and btate of Georgia, have invented certain new and useful Improvements in Block Signaling Systems, of which the following is a specification.

My invention relates to new and useful improvements in block signal systems for railroads, the primary object of my invention being the provision of a simple system by means of which a train passing in either direction along a track will receive warning of trains preceding it in the same direction, following it, or coming toward it along the same track and will also give warning to such trains.

4 A still further object of my invention consists in so arranging the block signal system that three successive warnings will be given,

the first consisting merely in the provision of a visible or audible signal device, the second in a warning application of the air brakes of the train and the third in an emergency application of the brakes.

A still further object of my invention is to so arrange the block signal system that it may be equally as effective for trains running backward as for trains going ahead and so arranged that in either case the trains upon their passage from a block will reset certain of the mechanisms previously set by the train, the arrangement being such that no train can approach within two blocks of another train without receiving l suitable warning.

A still further object of my invention is to accomplish the foregoing objects without the employ-ment of a third rail and without maintaining a iow of current through the track rails, the various circuits necessary being momemtarily closed between spaced contacts located adjacent the track rails and the track rails and also through the brake actuating circuits of the train, said circuits including brushes or other like contacts for engagement with the contacts disposed near the track.

4 A still further object of my invention is to provide a block signal system which may be quickly and cheaply installed and which will be effective in use and certain in operation.` u

"Vith these and other objects 1n View, my

invention will be more fully described, illustrated in the accompanying drawings and then specifically pointed out in the claims which are attached to and form aI part of this application.

In the drawings:

Figure l is a diagrammatic view of the mechanism carried by each locomotive operating over roads equipped with my block signal system;

Fig. 2 is a diagrammatic view showing three adjacent blocks and the equipment thereof, it being understood that all blocks are duplicates of each other.

Corresponding and like parts are referred to in the following description and indicated in all the views of the drawings by the same reference characters. Furthermore, inasmuch as the various contacts, switches and other parts of each block are identical with corresponding parts of all other blocks, I shall, in the blocks illustrated in the drawings, refer to the parts of but one block by their reference numeral and a distinguishing letter characteristic of such block. This reference is tobe considered as a description of the corresponding parts of the remaining blocks illustrated, which parts will be designated by the same numeral but with the distinguishing letter of their particular blocks in junction with the numeral.

Referring first to the track mechanisms, attention is particularly directed to Fig. 2 of the drawings in which '1.0 and l] indicate the usual rails, it being understood that these rails are each electrically bonded throughout the length ot the track in order that theyl may serve as parts of all metallic circuits. The track, as is usual in signaling systems or' this character, is divided into a plurality of blocks, the divisions in this figure being shown by transverse dot and dash lines. Each of these blocks may be of any suitable length and associated with each block are mechanisms controlling the setting of signals of certain blocks ahead and the resetting of signals of certain blocks at the rear. It will of course be understood that these mechanisms, in practice, will be inclosed in suitable housings mounted in any convenient position, usually adjacent the tracks, save for the Contact shoes which, of course, must be mounted near the rails and left exposed for engagement byI the train carried contacts. Those of the track shoes which coperate with the mechanism fon setting signals ahead of the train are located adjacent the entrance oi the respective blocks, while those controlling thefresetting l of signals at the rear are located adjacent the farther ends of their respective blocks.

I have illustrated, in Fig. 2, three blocks A, B and C, together with the mechanisms associated therewith. Referring to iblockzA,

shoes 14a and 16a are located,somewhat-tarther from the rail and the contact shoes 13a vvand 15a still farther yfrom the rail, Vall of the contacts,` above mentioned, .being consecutively numbered from the entrance ofthe block. :These contact shoes Vmay be of any :lengthvfound desirable and may be yspaced `any suitable distance apart although, as. a rule, they 'will be located relatively-.close to each lother. Disposed in a reverseimann'er, adjacent the track rail 11, are the iconita'ct yshoes 21a, "22%, 232242125, 26, .27, 28? and 29a. These contacts correspond to the:con tacts 12a to 20a vinclusive and are'fthose Iengaged by a car when passing through the block inthe opposite direction. A conductor 30a joins the contacts 13.a and 114, while a -conductor 'Slaejoins the contacts 22?l anda,

thelremaining contacts being freeot allelectrical connection with 1 all other co'ntacts. Each block in the .system is providediwith corresponding contacts or contact I shoes located in a similar manner, the corresponding contacts being given the same reference nui'neral but a characteristic distinguishing let- -ter-associated with the numeral.

*The blockA includes, as part of its mechanism, aswitch- 32a including opposed 'elec- 'tro-magnets` 33aand 84a 4between -whichis positioned a swingingly mountedarmature ,35a whichralsoA forms the switch blade,rits Afree lend being;` movable into `engagement with the contact SGfLwhen attractedbythe electro-magnet The block A-is further Aprovi-dedwuth a y'second `switch mechanism 37a including opposed velectro-magnets.i353n and 392L and a common swinginglymounted armature 40@ movable into engageinentfwith the con-tact alfL when the magnet `39L is energized. 4 The block A. is'` 4further provided `with a switch mechanism 42a including-'gopposed ymagnets 43.1 and 44a having acomin'on .armature 45a-forming a s\v1tch-blade and movable into engagement with a contact 46a when the magnet 43 is energized. A link Na connects this switch blade or armature withtheree end of aswitch blade 48a which is pivotally mounted intermediate its length and which, when the switch blade 45a engages the contact 46a, is adapted to bridge a rcircuit between the spaced contacts 49a and 50a. On the other hand, when the armature 45 is in its opposite position, this switch blade 4S is adapted tobridgea av circuit :throughf'the spaced contacts 5Fl/,and 152% Further the block A rincludes 'an .additional xswfitch Vmechanism 53% :including opposed electro-inagnets attfand :55a Landi a 'common armature hadapted,when attracted bythe electro-magnet "54a, to engage a i'Contact 57a.

Having thus described the track Contact lshoes and the cooperatingswitch mechanisins,y Iwwillmow describe therwiringxbetween them. :A foonzductor wire 5S-leads Yroinxthe contactshoe 1:2l tothefelectroimag-net 39lmand a wire 59bfleads `fromthis Vmagnet tothe track :rail 11. ik' conductor vire-i601 leads from the rtrack contact 142:3

.and consequently f'from, the. track s contact 13, Cthe ytwo .being electrically connected,V tothe switch contact 36a and a wire 61L1 leads from the switch blade 35a tothe wirefQa. A wire contact 246 fof ythe aswitch A12?" fand a wire-66)a -leadsrom theswitch ltto the track rail 10. aA wire-6ft21 -leads from the contactshoe 116 to the conta-ct 57H01t the-switch 53EL anda wire a'leads rfromthe switchbla'de fifto the wire 63@ and sorto thetrack .rail 10.

Awwire @66avr leads from the lcontact 17`1 to the electrofmagnet 43a., a wire 67a leads from 'this electro-magnet 48@ to the switch'conta'ct yswitch contact 51a to the electro-finagnetet and a wire G9 leads fromthis electro-maiglnet 541a to thewire G5a and so by way otthe wirePGB' to'ithe .track rail 10. A'fwire "70h -rleads from the track contact'shoe 18h tothe electro-magnet55" and a wire 71 leadsfrom this electro-magnet tothe wire' 65d. lAwire` 72f-leads .romfthe track fcontactshoe 19a to fthe electro-magnet 38 and a wire 73a `leads vfrom this "electro-magnetlto thefwire 59a and so toi the=track rail 11. A wire 74C leads ifromthe track contact 'shoe 20C to thefelectrom1agnet 44a and a wire .75 leads' from thiselectro-m'agnet to the wire '63a and so to .the-track rail 10.

Considering new the connectionsfromthe `track contacts fat the `other si de ofthetra ck, aiwire 76 leads -fromthe track contact 2lb to the electro-magnet 33 and awire A 77 'romthis electroemagnet tolthe wire 59ZLV land i so tothe track rail '11. A wire 78a" leads from the'tra'ck contact '22, 'and consequently the tra'ck contact 23@ to the switch vcontact 41a, a wire 79a leading from the switch-blade 40u-tothe wire 73a and so to vthe wire 59aL f and the track rail 11. A wire 91*1 leads from the track contact 24 to the Wire 62 and consequently to the track contact 15a.

,A wire S0a leads from the track contact 25n to the wire 64a. A wire 81a leads from the track contact 26n to the wire 66 and consequently to the track contact 17a. A wire 82a leads from the track contact 27a to the wire 70 and so to the track contact 18C. A wire 83a leads from the track contact 28EL to the electro-magnet 34.-a and a wire 84l leads from this electro-magnet to the wire 73a and so by way of the wire 59a 'to the track rail 11. A wire 85a leads from the track Contact 29 to that wire leading from the electro-magnet 441 to the contact 20 of the next block beyond block C.

Line wires 86 and 87, including any suitable source of electrical energy, not shown, preferably extend parallel to the track and at each block, branch wires 8S and 89 lead therefrom. The branch wire 88*L leads to the contact 19a and includes an electrically operated signal device as at 90, while the branch wire 89a leads to the contact 501.

Having thus described the track mechanism proper', together with its wiring, I will now describe the-co-acting mechanism carried by the train. It will of course be understood that each train is provided with a separate mechanism, preferably located in the locomotive as the locomotive always `forms one element of every train. Referring more specifically to Fig. 1 of the drawings, in which the mechanism is shown diagrammatieally, 92, 93 and 94 indicate contact brushes which are supported at the side of the locomotive, in any suitable manner, to permit them to engage the track contacts adjacent the rail 10. These contact `brushes are insulated from each other, the

lbrush 92 being adapted to engage the contacts 12, 17, 18, 19 and 20, the Contact brush 93 to engage the contacts 1-:1 and 16 and the contact brush 9-t to engage the contacts 13 and 15. Corresponding contact brushes 95, 96 and 97 are supported at the opposite side of the locomotive to engage the track contacts adjacent the rail 11 when the locomotive is backing along the track or to engage thel contacts adjacent the rail 10 when the locomotive is going ahead along the track in the other direction. It will therefore be seen that one set or the other of these contact brushes will be in position to operate irrespective of the direction in which the locomotive is traveling and whether it is being driven ahead or backward. In Fig. l I have illustrated a portion of a locomotive truck, conventionally, at 98 and one of the track contacts 16a adjacent the track rail 10. I have also shown, at 99, in broken lines, an electrical connection between the track rail 10 and the contact 16n to represent the closing of a circuit through the Wiring of .position of the switch.

the block signal system, the various switch mechanisms which may be in this circuit not being shown.

A wire 100 leads from one pole of a storage battery 101, or other suitable source of electrical energy, to the locomotive truck 98,- and consequently to the track rail. A. three bladed switch, indicated as a whole by the numeral 102 is mounted at any convenient point in the locomotive and includes switch blades 103, 1041 and 101 insulated from each other but adapted to be swung simultaneously, heilig pivoted to contacts 105, 106 and 106 respectively. These switch blades are adapted to engage either the contacts 107, 108 and 108', respectively, or the contacts 109, 110 and 110', according to the A wire 111 leads from the contact brush 92 to the switch contact 107, a second wire 112 also leads from the contact brush 92 to the switch Contact 108, and a third wire 112 leads from the contact brush 92 to the switch contact 108. A wire 113 leads from the contact brush 95 to the switch contact 109, a wire 1111 also leads from the contact brush 95 to the switch contact 110, and a wire 115 leads from the Contact brush 95 to the switch contact 110. A wire 1.1.6 connects the contact brushes 93 and 96, and a wire 117 connects the contact brushes 9L and 97. from the wires 116 and 117 to electro-magnets 1.21 and 122, respectively, while wires 123 and 124: lead from these magnets to the switch contacts 105 and 106, respectively, and a wire 11S leads from the other pole of the battery 101 to the switch contact 1.06.

Mounted at any convenient point, prefer ably within the locomotive cab, and communicating with the train pipe of the air brake system, is a valve, conventionally shown at 125 and so constructed that when partially opened, it will vvent the train line snflieiently to give a slight and gentle. application of the brakes, while, when more widely opened, it will give an emergency apj'ilication oi the brakes. The valve handle 126 is pivotally connected to a link 127 having a threaded end 128. The electro-magnets 121 and 122 are provided with swingingly mounted armatures 129 and 130, respectively, the free ends of which extend past each other and are slotted to receive the threaded end of the link 127. A nut 131 is threaded upon the link 127 to support the armature 130 in p such a manner that when attracted by its magnet 122, it will draw the link 127 a sufficient distance to open the valve for a gentle warning application of the brakes, the

extent to which the valve will be opened be- Y ing dependent upon the adjustment of the nut 131. The free end of the armature 129 engages between spaced nuts 132 threaded upon the link 127 in such a manner that upon energization of the magnet 121, the

Wires 119 and 120 lea-l valve 125 will be fully opened to-wgive an emergency application of the brakes. The electro-magnets are so arranged with respect to 'each other .that after "complete movement of the armature 130, because :of attraction by its magnet, the :armature '129 willstillbe a considerable distance from its magnet.

As will be more fullyr pointed out,the engagement of either of the contact brushes 92'and 95 vwith the track contactsin no way affects any circuits through theelectro-magnets 121l and 122, their function being merely to close certain trackcircuits which either set `or reset the various'switch mechanisms of the blocks during the passage of the train. @n the othcrhanck assuming that the switch 102 is in the position shown in Fig. 1, an engagement yof ythe `contact brush. 97 with a track contact in electrical circuit with either of the rails 10 or 11 will cause energization of theV electro-magnet 122, current passing from the battery 101,

-wire 100, locomotive truck 98, rail 10 or 11,

as the case may be, and through the track circuit, as willbe later explained, to the brush 97, vthrough the wire 117 'and wire 120 to the electro-magnet 122, through the wire 124 and switch blade 108 to the wire 114, to the contact brush 95 and fromthis brush through the wire 115, switch 'fblade 104 `*and* wire 118 to the battery. Inllike `manner, a corresponding `circuit through the magnet 122 will be formed if the switch 102 is in reverse position, upon engagement lof the contact brush 94 with a track contact in electrical connection with one -of the vtrack rails.

Again, if the switch is in the position shown and the contact brush 96 engages a track contact in' electrical circuit with one of the track rails, a Acircuit will be formed through the electro-magnet 121, current passing from the battery through the wire 100, locomotive truck 98, track rail 11 and track circuit to that contact engaging the brush 96 through the wire 116 and wire 119 to the magnet 121, through the wire 123 and switch blade 104 and wire 118 to the'brush 95 and from this brush through the wires 115 and 1181to the battery. Furthermore, with the switch reversed, if the brush 93 en- 1 gages a track contact in electrical'connection with either'track rail, as shown in Fig. 1, a circuit will be formed through the electro-magnet 121.

At this point it should be noted that all circuits formed through the electro-magnets pass through one or the other of the brush contacts 92 'and 95 depending upon which set .of contacts is in usev and that forthis reason either set of vcontactsm'aybe rendered inoperative by'proper'positioning of lthe switch 102. For instance, if the train is proceeding ahead in either `direction along Athetrack, the'contact brushes 92, 98 and 94 will "be-employed, while if they-train is backing in either direction, the contact brushes 95, 9G vand A97 willy be employed.

`1t-will therefore be seen that the track Vmechanisms :previously described need only "be so arranged `as to electrically connect ceritainof the track contacts with the track 'lr-ails, under certain conditions, and to, un-

'andthe' wiring of lthe 'train carried mechanism, I will now explain the operation ofthe block signal system as a whole. For the' purpose of clearness in this explanation, I will first explain-the operation of the system 'by means of which rear end collisions lbetween trams following each other along lthe track are avoided, assuming first that atrain is lat a point substantially midwayof block A and proceeding in thel direction ofblock B,the contact brushes 92, 93 and 94l of this tra-in beingv connected in circuit -with the battery 101, while the-brushes 95,

96 and 97-fare out ofv circuit. Under these =conditions,when the' contact brush 92 engages the trackcontact shoe 17a, current will l'fiow from the battery` 101 through the wire 100to the track raily 10, through the wire fiwire 65, wire 69, electro-magnet 54,

wire 68a, switch `blade 48, it being assumed that the armatures 55aand 45a are in a reverse position to thatl shown, wire 67, electromagnet 43a, wire 66a to the contact slice 17a, brush 92, wire 115 and wire 118 to the battery. This circuit will energize the electrof magnets 43a and 54a to move their armatures to thepositions shown in thedrawings and to move the switch blade 48a to the position there shown. This movement ofthe switch `blade 48a closes the circuit through the signal light 90a, the result being that block Alias its signal light displayed and also lhas its signal system set, as will be klater fully explained, to give both warning and vemergency brake applications-to a following train. As the remaining contact shoes between 17 1 land the left end of the block deal with the `resetting mechanism ofthe block setting system, they will, for the moment, be neglected and 'I will assume that the train'has proceeded to the position shown 'conventionally by a portion of a truck at the extreme left end of block A. Suppose 'now a train enters block A from the block at the 'right and considering only such contact shoes as have to do with the safe guarding of block A from a train following the first. Under `these circumstances, the conatact brush 94 of the following train will *engage thecontact shoe 15a. A circuit'will then be formed from the battery 101 of the following train, through the wire 100 to the track rail 10, from this rail through the wire 63, switch blade 45, wire 62, contact shoe 15, contact brush 94, wire 117, wire 120, electro-magnet 122, wire 124, switch 102, wire 114 contact brush 95, Wire 115 and wire 118 to the battery. This circuit will energize the electro-magnet 122 upon the second `train to slightly open its air brake valve 125 and give ak warning application of the brakes. Of course it will be understood that the engineer may stop his train before receiving this warning application if he notices the signal light 90".

1f, however, the engineer pays no attention either to the signal light or the warning application of the train and the train still proceeds through block A, its contact brush 93 will then engage the contact shoe 16. Under these circumstances, a circuit is formed from the battery 101, through thc wire 100, to the track rail 10, through the wire 63, wire 65, switch blade 56, Wire 64, contact shoe 16, contact brush 93, wire 116, Wire 119, electro-magnet 121, wire 123, switch 102, wire 113, contact brush 95, wire 115 and wire 118 to the battery. This circuit Will energize the electro-magnet 121 and give an emergency application of the brakes, bringing the train to an absolute stop. It will thereforebe clear that itwill be impossible. for a train to follow another one into a block already occupied by the train being followed.

It will of course be understood that the train ahead has been protected in the same manner all through the preceding blocks.

Assuming now that the leading train, that is, the one at the eXtreme left end of block A proceeds on its way. Upon approaching the left end of block B its contact brush 92 will engage the track contact shoe 17b to close a circuit through the electro-magnets 43 and 54" in the manner previously described in connection With block A and to therefore set block B against a following train. This saine brush will then engage the contact shoe 18b to close a circuit from the battery through the wire 100, track rail 10, wire 63, wire 65, wire 71, electromagnet wire 70b to the contact shoe 18", the contact brush 92, wire 115 and. Wire 118 to the battery. Under these circumstances, the switch 53 is opened. This switch 53, as we have seen, is the switch through which the circuit for an emergency application of the lbrakes of a following train is closed. It will therefore be clear that after the first train has reached the track contact 18b of. block B, a train entering block A will receive only a warning application of the brakes.

As the leading train proceeds from block B into block C, its contact brush`92 will engage the contact shoe 17 to close the switches 42 and 53 in the manner eX- plained in connection `with the preceding blocks. It will then engage the contact shoe 18 to open the switch 53 in the manner explained in'connection with block A. After this, it will engage the contact shoe 20 closing a circuit from the battery 101, throuh the wire 100, track rail 10, wire 63, wire 75, electro-magnet 44, wire 74, contact shoe 20, contact brush 92, wire 115 and wire 118 to the battery. This circuit opens the switch 42, and consequently the switch 48, thereby completely clearing block A.

We have therefore seen that the contact shoes 15, 16, 17, 18 and 20, together with the switches 43, 48 and 53, control themechanism for the avoidance of rear end collisions, the contacts 15 and 16 being those which close the brake operating circuits upon a following train, the contact 17 that which sets the mechanism in the block which the train is leaving, the contact 18 that which opens the emergency controlling switch in the block at the rear of the train and the contact 20 that which opens the warning application switch in the second block to the rear of the occupied block;

An examination of the contact shoes ad' jacent the track rail 11 will showtliat they correspond to similar shoes adjacent the track rail 10 and will operate in like manner for trains following each other 'along the track from block C toward block A. A detailed description of their operation is believed to be unnecessary as being substantially identical with that above described.

Before giving a description of the block signal system in connection with approaching trains, I wish to point out that the position of the switches 32 and 37, which are switches controlling the signal system for this purpose, are normally in the position. shown in blocks A and C. The switches 37 are released by the magnets 38 and closed by the magnets 39, the closing of circuits through these magnets being governed by the track contacts 12 and 19 adjacent the track rail 10, and consequently by trains passing from the right to the left, that is, from block A toward block C, while the switches 32 are released by the magnets 34 and closed by the magnets 33, the circuits through which are controlled by engagement with the track contacts 21 and 28 adjacent the track rail 11, and consequently by trains passing along the track in the opposite direction, that is, from the direction'of block C toward block A.

Assuming that a train enters block A, moving toward block C, its contact brush 92 will engage the track contact shoe 12. Under these conditions, a circuit will be closed from the battery 101 of such train,

throughthe Wire 10,0,"track rail 11, Wire 59b tothe electro-magnet 39", through" the Wire 5S2L to the contacty shoe 12a, Contact brush. 92,Wire', 115l and Wire 118 to the battery.y This will` close the switch 37Vb and set` block B against a train approaching fromV block` C. Assuming ya train approaches from block C, its contact brush 92 will engage the contact shoe 21b closing a circuit from the battery 101 ot' its locomotive equipment through the Wire 100, track rail 11,

Wire-59, Wire 77a, electro-magnet 33a, Wirey 76h, contact shoe 2lb, contactbrush 92,Wi re 1151 and Wire, 118 tothe battery. Thistvill close the switch 32a and, as Will be lateraeX-i plained, close `block A againstia train approaching Afroml theright.

As soon as thesecond train, approaching block A from, the directiony of block C, has advanced Isuliiciently to bring its contact shoe9-1= into engagementwith the contact brush 22% a circuit -will be closedfrom the battery 101 of such-train, through the` Wire 100, track rail 11, Wire 59h, Wire 7 9F, switch L blade 10b, Wire 78", contact shoe 22h, contact brush 9e, Wire 117, vvire 120, `electro.- inagnet122, Wire 124, switch 102, -`Wire 11e, Wire yllrand wire118 to the battery. This Will energize themagnet 122 upon the trainV approaching from block C and give a Warning application of the brakes upon such 1tl the train approaching from block C had' set'block A against a train approaching in the opposite, direction before such train entered v.block A, similar circuits Would be closed through the brake actuating. mechanism of such train .When its-contact brushes 94 and 93 engagethe track contact shoes13a and 14a.; As these circuits are formedin the same manner. as those above described, this explanation need notbe repeated.

lA will assume, however, .that the trainv ap.- piroaching from the right had alreadyy passed the -trackcontacts 13a. and. 14a., Ot course ift'pthi'sivere the case,A the train approaching block A from block C would .be stopped op-V posite the trackcontact sli0e/ ..2f. However, av 4train approaching block B.. in block A would.. ycontinue until V'it entered.v :blockB "and engaged the contact shoes` 13bi and Illlbavvhe'n rst'a Warning and then an. emergency appl-i,

leemte cation ot the brakes would be received by closing of circuitsthrough the switch 32h, which switch had l.been set against a train approaching from the direction ot block A by the train approaching from the direction of block Crivhen entering block C. Therefore, it Will be seen that the train approaching from block C Will be stopped opposite the contactshoe 23D, While the train approaching from ,block r1 `Will be stopped opposite the contact 14th. will `be brought to an absolute stop at a distance ot nearly a block from each other.

In orderto explain the resetting of the signaling system, Iivill assume that a train has entered block A from the right, that is, moving toward block C and has set block B, as previously explained, vagainst a train ap pro-aching from block Ctoivard block A; 1 Will further assume that conditions are normal,-that is, there is no train approaching Tn .other Words, the trainsY tact brush engages the track contact shoe 19h. Under this condition, a circuit Will be formed yfrom the battery 101, through the Wire 100, track rail 11, Wire 59h', Wire 731?, electro-magnet 38h, Wire 72", track contact shoe 19h.; contact brush 92, WireV 115 `and WireI 118 to the battery. This circuit'vvill energize the electro-magnet 38h and open the switch 37", therebv clearing block `B againstav train'approaching'froni the direction of block C and leaving the block in its origi-l nal condition.

From the foregoing description, it will be apparent that the block setting and resetting` or releasing `mechanism for setting and re-v setting the blocks against follovvingtrains and for setting and resetting theA blocks against approaching trains in no vvay` interfere `With each other and that all trains Will` operate the block 'signal system to auto-maticallv keep trains `from approaching Within one block ot them in either directionn Itivill of course be understood that I do not Wish to limit mvselfto the specific brake valve controlling and actuating mechanism, as illustrated in Fig. 1. as various other devices or systems vmay be found applicable in connection with the track Wiringl system shown inFig. 2. For instance, thertorin of brake actuatingv mechanism disclosed in my copcnding application. for .fi-safety appliance for railway trainaled July 6, 1913 and bearing 4the Serial No. 746,6501may beemlployed in place oit the above described mechanisin if preferred.

Having thus described the invention. what is claimedas new is: I i

1. 'Ablock signalsystem:including` a track,

a plurality oi circuit breakers, a plurality of contacts adjacent the track, circuits norinally open' between certain contacts and the track for closing the circuit breakers when the circuits are closed, circuit-s normally open between certain other contacts and the track for opening the circuit breakers when such circuits are closed, circuits through the circuit breakers when the latter are closed which are open between certain other contacts and the track,` air valve controlling mechanism carried by the locomotive, circuits upon the locomotive including contact shoes adapted for engagement with the latter contacts to operate the air valve controlling mechanism when said latter track circuits are closed, additional circuits upon the locomotive including contact shoes adapted for engagement with the first mentioned contacts for completing circuits between said contacts and the track to close the circuit breakers, and still further circuits upon the locomotive including contact shoes for engagement with the second mentioned contacts for closing circuits between them and the track for opening the circuit breakers.

2. A block signal system including electrically bonded track rails, a locomotive carried air brake valve, magnets for giving warning and emergency openings to the valve, locomotive carried signal circuits, certain ont' which pass through the magnets, each signal circuit including a contact brush, contact slices disposed adjacent the track and engageable by the brushes, and means including relays operable by engagement of certain shoes by the' brushes in said signal circuits not through the magnets for placing certain other shoes in electrical connection with a track rail, whereby engagement with one of said latter shoes by one of the brushes in circuit with one of the magnets will close its circuit.

3. A block signal system including electrically bonded track rails, a locomotive carried air brake valve, magnets for giving warning and emergency openings to the valve, locomotive carried signal circuits, certain of which pass through the magnets, each signal circuit including a contact brush, contact shoes disposed adjacent the track and engageable by the brushes, means including relays operable by engagement of certain shoes by the brushes in said signal circuits not through the magnets for placing cert-ain other shoes in electrical connection with a track rail, whereby engagement with one of said lattershoes by one of the brushes in circuit with one of the magnets will close its circuit, and means operable by engagement of certain shoes by certain brushes not in the magnet circuits 'for rendering the shoes which have been placed in electrical connection with a track rail inactive.

4t. A block signal system including electrically bonded track rails, a locomotive carried air brake valve, magnets for giving warning and emergency openings to the valve, locomotive carried signal circuits, certain of which pass through the magnets and each of which includes a contact brush, contact shoes disposed adjacent the track and engageable by the brushes, means including relays operable by engagement of certain shoes by the brushes in said signal circuit not through the magnets for placing certain other shoes in electrical connection with a track rail, whereby engagement with one of said latter shoes by one of the brushes in circuit with one of the magnets will close its circuit, a track signal circuit, and means operable by one of the relays controlling the signal circuit.

5. In block signal systems, a track, a plurality of track contacts, a train carried signal circuit, a train carried circuit for controlling track circuit conditions, each of such circuits having brushes for engagement with the track contacts, a pair of relays adapted to be energized by engagement of certain of the brushes with one of the track contacts and when energized to electrically connect a pair of track contacts with the track, and a pair of spaced track contacts in circuit each with one of the relays whereby the relays will be successively returned to normal by engagement of the pair of track contacts by one of the brushes.

6. In block signal systems, a track, a plurality of track contacts, a train carried signal circuit, a train carried circuit for controlling track circuit conditions, each of such circuits having brushes 'for engagement with the track contacts, a pair of relays adapted to be energized by engagement of certain of the brushes with one of the track contacts and when energized to electrically connect a pair of track contacts with the track, a pair of spaced track contacts in circuit each with one of the relays, whereby the relays will be successively returned to normal by engagement of the pair of track contactsV by one of the brushes, a track signal circuit, and a switch controlling the track signal 'circuit and operated by one of the relays.

In testimony whereoi1 I a'tlix my signature in presences of two witnesses.

ROBLEY C. MILLARD. [1.. s] l/Vitnesses:

W. HAL Minnen, W. S. Hess.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

